Human activities in the home (i.e., those associated with home energy use) are directly responsible for 28% of U.S. energy consumption. Most people, however, are unaware of how their daily activities affect the environment or how often they engage in those activities. Feedback regarding energy consumption, which can provide such awareness, has been shown to be one of the most effective strategies in reducing electricity usage in the home. Thus, with the advent of new sensing technologies and advances in machine learning, it would be desirable to provide personal, relevant feedback about energy usage in real-time, for a variety of energy consuming activities.
Many researchers in the ubiquitous computing (ubicomp) and Human-Computer Interaction communities have seized the opportunity to explore a variety of applications for helping individuals reduce their overall energy use. One particularly important piece of information is real-time, whole house power use, which can be obtained using one of a number of commercially available electric current/power sensors.
However, these sensors typically require professional installation to avoid concerns about the safety of a homeowner who might attempt the job, because the sensors are typically installed around the hot and/or neutral power feeds coming into the home in the main circuit breaker box. Most homeowners are neither trained for this type of installation nor confident (with good reason) that they can accomplish the installation without possibly electrocuting themselves or causing other damage. Accordingly, it would be desirable to employ a contactless, whole house current/power sensor that can easily be installed by an unskilled homeowner and which can enable widespread exploration of electricity monitoring applications. Even if such a sensor is used as a standalone device that simply provides a continuous indication of electrical current and/or power usage within a living structure, the information thus provided can be valuable in enabling the residents to adjust or modify their activities so as to reduce electric power consumption.
The least costly of current sensing devices that can be safely installed by a non-skilled homeowner include the KILL-A-WATT™ and WATTS UP™. However, these devices simply measure the energy used at a single outlet and display the data only on the device at that point. The two most popular and inexpensive whole house sensing systems are THE ENERGY DETECTIVE™ (TED™) and the POWERCOST™ monitor. The TED™ monitor uses a coil-based current sensor installed inside a home's main circuit breaker panel, while the POWERCOST™ monitor uses a sensor attached to the face of the home's power meter. Both devices offer a variety of display modes from current energy consumption in kilowatts or dollars, to energy consumed each day or since the last energy measurement cycle. The POWERCOST™ sensor is the easiest to deploy and can be installed by a homeowner; however, it relies on electromechanical and electronic watt-hour meters that have an exposed optical port. Thus, this solution is constrained to specific types of watt-hour meters and may not, for example, be suitable for apartments, where the power meter might not be easily accessible. It would therefore be desirable to provide an alternative solution that is very flexible and can be used in any home or apartment (or other structure) where there is a circuit breaker panel for the metered space, which is required by many national electrical codes.
Installation of a power monitoring device by an unskilled person should be safe and relatively easy. It should be possible to use such a device for many applications requiring electrical current and/or power usage. For example, by providing an integrator capability, the device should be able to measure energy used by a structure, effectively taking the place of a conventional electromechanical or electronic watt-hour meter. A further benefit of using a contactless current/power and energy measurement device would be to provide time-of-day monitoring of energy consumption, to enable lower cost energy rates to be achieved at minimal cost to both the power utility company and the owner of a structure. These and other applications of an safe and accurate power monitoring device will be evident from the following disclosure.